Method and apparatus for treating bone fractures, and/or for fortifying and/or augmenting bone, including the provision and use of composite implants

ABSTRACT

A composite implant comprising an injectable matrix material which is flowable and settable, and at least one reinforcing element for integration with the injectable matrix material, the at least one reinforcing element adding sufficient strength to the injectable matrix material such that when the composite implant is disposed in a cavity in a bone, the composite implant supports the bone. 
     A method for treating a bone, the method comprising:
         selecting at least one reinforcing element to be combined with an injectable matrix material so as to together form a composite implant capable of supporting the bone;   positioning the at least one reinforcing element in a cavity in the bone;   flowing the injectable matrix material into the cavity in the bone so that the injectable matrix material interfaces with the at least one reinforcing element; and   transforming the injectable matrix material from a flowable state to a non-flowable state so as to establish a static structure for the composite implant, such that the composite implant supports the adjacent bone.

REFERENCE TO PENDING PRIOR PATENT APPLICATIONS

This patent application:

(i) is a continuation-in-part of pending prior U.S. patent applicationSer. No. 13/452,273, filed Apr. 20, 2012 by Jeffrey A. D'Agostino et al.for IMPLANTABLE POLYMER FOR BONE AND VASCULAR LESIONS (Attorney's DocketNo. 111137-0002), which patent application in turn (a) is acontinuation-in-part of prior International (PCT) Patent Application No.PCT/US2011/057124, filed Oct. 20, 2011, and (b) claims benefit of priorU.S. Provisional Patent Application Ser. No. 61/394,968, filed Oct. 20,2010; and

(ii) claims benefit of pending prior U.S. Provisional Patent ApplicationSer. No. 61/604,632, filed Feb. 29, 2012 by Jeffrey D'Agostino et al.for SPLINT INJECTION (Attorney's Docket No. 0330.00005; 206 ORTHO-1PROV).

The four (4) above-identified patent applications are herebyincorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to methods and apparatus for treating bones, andmore particularly to methods and apparatus for treating bone fracturesand/or for fortifying and/or augmenting bone in mammals.

BACKGROUND OF THE INVENTION

It is common for bones to become fractured as the result of a fall, anautomobile accident, a sporting injury, etc. In these circumstances, itis common to reinforce the bone in the area of the fracture so as tosupport the bone during healing.

To this end, current treatment options typically comprise externalstabilizers (e.g., plaster casts, braces, etc.) and internal stabilizers(e.g., screws, bone plates, intramedullary nails, etc.).

External stabilizers such as casts and external braces suffer from anumber of disadvantages. For one thing, they can interfere with apatient's normal daily activities, e.g., it can be difficult to wearclothing over a cast, or to operate a motor vehicle with a cast, etc.Furthermore, with animals, external casting and bracing of somefractures can be extremely difficult. In addition, with externalstabilizers, the soft tissue interposed between the bone and theexternal stabilizer is used to transmit load from the bone to theexternal stabilizer. As a result, shortly after application of theexternal stabilizer, the patient's intervening soft tissue will begin toatrophy through disuse, thereby requiring further rehabilitation for thepatient. Furthermore, as the intervening soft tissue atrophies, theclose supporting fit of the external stabilizer is disrupted and, as aresult, effective load transfer is undermined.

Internal stabilizers such as screws, bone plates, intramedullary nails,etc. generally provide a more effective stabilization of the fracture,since they are able to directly interface with the bone. However,installing these internal stabilizers requires an invasive surgicalprocedure, e.g., a relatively large incision, etc. Furthermore, afterhealing of the fracture, the internal stabilizers (screws, bone plates,intramedullary nails, etc.) should, ideally, be removed so as to allowthe bone to fully recover its mechanical strength. This, however,requires a second surgical procedure, with additional trauma to thepatient.

In some circumstances (e.g., such as with fractures in vertebralbodies), bone cements may be injected into the interior of the bone inan attempt to stabilize the bone. However, such bone cements suffer fromdisadvantages of their own. More particularly, such bone cements aretypically ceramic cements, polymer-based cements (e.g., polymethylmethacrylate, also known as PMMA) or calcium salt-based cements. Whilethese bone cements are typically capable of withstanding significantcompressive loading, they are also extremely brittle and typicallycannot withstand significant tensile loading. This limits theirapplication in instances where the loading on the bone may include atensile component. This means that bone cements are not suitable for usein many situations, particularly in long bones (e.g., the tibia).

Thus it will be seen that a new approach is needed for treating bonefractures.

In addition to the foregoing, in some circumstances a medical condition(e.g., osteoporosis) can weaken or damage a bone, including the creationof voids within the bone, and it may be desirable to fortify and/oraugment a bone so that it can better withstand the forces associatedwith normal physical activity. Unfortunately, however, theaforementioned external stabilizers, internal stabilizers and bonecements have all proven inadequate for fortifying and/or augmenting abone, e.g., for the reasons given above.

Thus it will be seen that a new approach is also needed for fortifyingand/or augmenting a bone.

SUMMARY OF THE INVENTION

The present invention provides a new approach for treating bonefractures.

The present invention also provides a new approach for fortifying and/oraugmenting a bone.

More particularly, the present invention comprises the provision and useof a novel composite implant for treating bone fractures and/or forfortifying and/or augmenting a bone. The composite implant is disposedwithin the intramedullary canal of a bone, or within another opening inthe bone, so as to function as an internal “splint”, whereby to carrythe stress created during patient activity. This allows a bone fractureto heal, or provides fortification and/or augmentation of a bone, withminimum inconvenience to the patient. The composite implant comprises aplurality of components that are introduced sequentially into thepatient, and assembled in-situ, wherein each of the components has asize and flexibility which allows it to be installed using a minimallyinvasive approach while collectively providing the required structuralreinforcement for the bone which is being treated. Significantly, theproperties of the composite implant can be custom tailored for differenttreatment situations, e.g., the composite implant can have differentlengths and/or different cross-sectional dimensions, the compositeimplant can have different compressive and/or tensile strengths, etc.,all according to the individual needs of a particular patient.

In one preferred form of the invention, the composite implant comprisesthree components: a containment bag, one or more reinforcing elementsand an injectable matrix material.

The containment bag serves to protect the remaining components of thecomposite implant from the ingress of blood and/or other bodily fluidsthat might interfere with the deployment of the one or more reinforcingelements and/or interfere with the deployment or solidification of theinjectable matrix material. The containment bag also serves to constrainthe flow of the injectable matrix material while the injectable matrixmaterial is in its injectable state. The containment bag is flexible andmay be fabricated from a resorbable polymer such as a polyurethane,polylactic acid, glycolic acid or some mixture/copolymer thereof.Alternatively, the containment bag may be formed from fibers that arewoven, braided, knit, nonwoven, and/or otherwise worked so as to form amesh bag. Suitable fibers include polylactic acid, polyglycolic acid,polydioxanone or mixtures/copolymers thereof. In any case, thecontainment bag preferably has sufficient strength to allow theinjectable matrix material to be injected into the containment bag undersubstantial pressure so as to ensure good interfacial contact betweenthe injectable matrix material and the one or more reinforcing elements,and to minimize voids within the containment bag, and to ensure goodinterfacial contact between the composite implant and the bone. Ideallythe mesh bag is hydrophobic so as to minimize the ingress of bodilyfluids into the containment bag that may otherwise interfere with thedeployment or solidification of the various components of the compositeimplant. Alternatively, the mesh bag may have a limited porosity toallow some egress of the injectable matrix material out of thecontainment bag, e.g., to osseointegrate with the surrounding bone. Thecontainment bag may have a hydrophobicity and porosity that affects thebiocompatibility and degradation of the composite implant by modulatingthe ingress of water into the interior of the containment bag.

The one or more reinforcing elements comprise (i) flexible reinforcingsheets (which are preferably in the form of flexible concentricreinforcing tubes or flexible rolled reinforcing sheets), with theflexible reinforcing sheets comprising filaments formed into a textile(i.e., woven, braided, knit, nonwoven, and/or otherwise worked so as toform the flexible reinforcing sheets) or incorporated into a film so asto form the flexible reinforcing sheets, (ii) flexible reinforcing rods,with the flexible reinforcing rods comprising a plurality of filamentswhich are held together by an outer sheath of a textile or film (whichmay or may not have the same composition as the aforementioned flexiblereinforcing sheets), or by a compacted (wound or compressed, etc.)connecting structure of a textile or film, or by a binder such as anadhesive, with or without surface projections for improved integrationwith the injectable matrix material, (iii) particulates (e.g.,particles, granules, segments, nanotubes, whiskers, nanorods, etc.), or(iv) combinations of the foregoing. Where the one or more reinforcingelements comprise flexible reinforcing sheets and/or flexiblereinforcing rods, the one or more reinforcing elements preferably havesufficient column strength to allow longitudinal delivery into thecontainment bag by pushing, and preferably have a configuration (e.g.,smooth outer surfaces, tapered ends, etc.) to facilitate movement pastother reinforcing elements and/or intervening structures (e.g., catheterstructures). Furthermore, where the one or more reinforcing elementscomprise flexible reinforcing sheets (e.g., concentric tubes or rolledsheets) which are intended to be radially compressed during delivery tofacilitate passage through a small opening (e.g., a catheter or surgicalopening), the flexible reinforcing sheets (e.g., concentric tubes orrolled sheets) may comprise resilient elements (e.g., resilient rings)to assist their subsequent return to an expanded state when positionedwithin the containment bag.

The filaments and particulates used to form the aforementionedreinforcing elements may be biodegradable or bioabsorbable, ornon-biodegradable or non-bioabsorbable. By way of example but notlimitation, suitable biodegradable or bioabsorbable materials includepolyglycolide (PGA), glycolide copolymers, glycolide/lactide copolymers(PGA/PLA), glycolide/trimethylene carbonate copolymers (PGA/TMC),stereoisomers and copolymers of polylactide, poly-L-lactide (PLLA),poly-D-lactide (PDLA), poly-DL-lactide (PDLLA), L-lactide, DL-lactidecopolymers, L-lactide, D-lactide copolymers, lactide tetramethyleneglycolide copolymers, lactide/trimethylene carbonate copolymers,lactide/delta-valerolactone copolymers, lactide/epsilon-caprolactonecopolymers, polydepsipeptide (glycine-DL-lactide copolymer),polylactide/ethylene oxide copolymers, asymmetrically 3,6-substitutedpoly-1,4-dioxane-2,4-diones, poly-βhydroxybutyrate (PHBA),PHBA/beta-hydroxyvalerate copolymers (PHBA/PHVA),poly-beta.-hydroxypropionate (PHPA), poly-beta-dioxanone (PDS),poly-DELTA-valerolactone, poly-DELTA-caprolactone, methylmethacrylate-N-vinyl pyrrolidone copolymers, polyester amides, oxalicacid polyesters, polydihydropyrans, polypeptides from alpha-amino acids,poly-beta-maleic acid (PMLA), poly-beta-alkanoic acids, polyethyleneoxide (PEO), silk, collagen, derivatized hyaluronic acid and chitinpolymers, and resorbable metals, resorbable ceramics, and solubleglasses. By way of further example but not limitation, suitablenon-biodegradable or non-bioabsorbable materials include polyolefins,polyamides, polyesters and polyimides, polyetheretherketone (PEEK), andcarbon fiber, and metals, ceramics, and glasses.

As will hereinafter be discussed, the one or more reinforcing elements15 are selected by the physician so as to provide the composite implantwith the desired size, stiffness and strength. Thus, and as willhereinafter be discussed, the physician may select from a variety ofdifferent reinforcing elements, each having a particular composition andlength, and preferably deliver those reinforcing elements sequentiallyto the patient, whereby to provide the composite implant with thedesired size, stiffness and strength. The physician may, optionally,size the reinforcement elements to the appropriate length.

The injectable matrix material is preferably polymeric and is preferablybiodegradable. The matrix material is preferably a multi-componentpolymer system that is mixed immediately prior to introduction into thepatient. Optionally, the injectable matrix material may contain abiocompatible solvent, with the solvent reducing viscosity so as toallow the matrix material to be injected, and with the solventthereafter rapidly diffusing from the composite implant so as tofacilitate or provide stiffening of the composite implant. The solventmay also be used to alter the porosity of the injectable matrixmaterial.

In one preferred form of the invention, the injectable matrix materialis preferably an organic polymer that can be formed via a polymerizationprocess.

If desired, the injectable matrix material may also comprise a bioactivefiller material, a therapeutic agent, and/or an agent to enhancevisibility while imaging the composite implant.

The composite implant is disposed within the intramedullary canal of abone, or within another opening in the bone, so as to function as aninternal “splint”, whereby to carry the stress created during patientactivity. This allows a bone fracture to heal, or provides fortificationand/or augmentation of bone, with minimum inconvenience to the patient.The components of the composite implant are introduced sequentially intothe patient, and assembled in-situ, thereby allowing the compositeimplant to be installed using a minimally invasive approach.

By way of example but not limitation, the composite implant may be usedin the following manner to treat a fracture in the tibia.

The first step is to create an access hole into the bone that is to betreated. When treating fractures in long bones, the hole is made intothe intramedullary canal distal to, or proximal to, the fracture site.

The second step is to remove or harvest the bone marrow (and/or othermatter) in the intramedullary canal, and to clean the intramedullarycanal, so as to provide a space for the composite implant. This is donethrough the access hole previously created. In one preferred form of theinvention, the device for removing or harvesting of the bone marrow fromthe intramedullary canal comprises a catheter with provision forintroducing a liquid or gas into the intramedullary canal and suctionfor removal of material from the intramedullary canal. The liquid or gascan be used to disrupt the content in the intramedullary canal orprepare the intramedullary canal for a composite implant. The liquid orgas can be introduced in a continuous, pulsed, or intermittent flow. Arotatable flexible rod, with a shaped end or attachment at the distalend, is optionally used to disrupt the bone marrow in the intramedullarycanal so as to aid in the removal of the bone marrow. When harvest ofthe bone marrow is required, a tissue trap is utilized.

The third step, if needed, is to place a flow restrictor plug in theintramedullary canal distal to, and/or proximal to, where the compositeimplant will be placed in the intramedullary canal. Again, this is donethrough the access hole previously created. The flow restrictor plugsmay be placed prior to the removal or harvest of the bone marrow (and/orother matter) to define the area to be cleaned. Where two flowrestrictor plugs are used, the two flow restrictor plugs may beconnected to one another.

The fourth step, if needed, is to return the bone to proper alignment.

The fifth step is to introduce the containment bag into theintramedullary canal via the access hole previously created. In onepreferred form of the invention, the containment bag is introduced intothe intramedullary canal through a delivery catheter, and is releasablyattached to a catheter that is used for subsequent delivery of theremaining components of the composite implant, i.e., the one or morereinforcement elements and the injectable matrix material. Note that theflexible (and compressible) nature of the containment bag facilitatesits delivery into the intramedullary canal via a minimally invasiveapproach (i.e., via the access hole previously created). The containmentbag may comprise an auxiliary channel to allow monitoring and control ofsubsequent pressure within the containment bag. The auxiliary channelmay be used to remove entrapped air from the composite implant duringfilling of the containment bag with the injectable matrix material. Theauxiliary channel may also be used to pressurize the injectable matrixmaterial so as to enhance bonding of the injectable matrix material withadjacent structures (e.g., the reinforcing elements, the containmentbag, bone, etc.). This auxiliary channel may be parallel to the deliverycatheter, or inside the delivery catheter, or the auxiliary channel maybe at the distal end of the containment bag. Alternatively, there may bea valve at the distal end of the containment bag, or at other strategicregions of the containment bag, that can limit pressure within thecontainment bag.

The sixth step is to sequentially introduce the one or more reinforcingelements into the containment bag. This is done through the access holepreviously created. Note that the flexible nature of the reinforcingelements facilitates their delivery into the containment bag via theaccess hole previously created. The one or more reinforcing structuresare preferably introduced into the containment bag sequentially so as tobuild up a reinforcing mass. In one preferred form of the invention, aplurality of flexible concentric reinforcing tubes are sequentiallyinserted into the containment bag, with one flexible reinforcing tubebeing nested inside another, and a plurality of flexible reinforcingrods are sequentially inserted within the innermost concentricreinforcing tube. In one preferred form of the invention, the flexiblereinforcing sheets (which are preferably in the form of concentric tubesor rolled sheets) are delivered to the interior of the containment bagby pushing them out of a delivery tube or, alternatively, by carryingthem into the containment bag while held within a delivery tube and thenretracting the delivery tube, whereby to expose the flexible reinforcingsheets. Preferably the size and number of concentric reinforcing tubesand reinforcing rods are selected so as to meet the individual needs ofa particular patient. The number of concentric reinforcing tubesutilized in the composite implant, and/or their lengths and/orcross-sectional dimensions, and/or the number of reinforcing rods used,and/or their lengths and/or cross-sectional dimensions, may be selectedaccording to the individual needs of a particular patient. Preferablythe number, length, and cross-sectional dimensions of the reinforcingtubes, and the number, length, and cross-sectional dimensions of thereinforcing rods, are selected so as to provide a composite implanthaving variable stiffness along its length, e.g., a composite implanthaving a stiffer central region (e.g., 20 GPa) and less stiff distal andproximal ends (e.g., 3 GPa), whereby to prevent stress risers from beingcreated at the ends of the composite implant. To this end, thereinforcing tubes, and the reinforcing rods, are preferably provided ina variety of sizes with a range of mechanical properties for appropriateselection by the physician; alternatively, the reinforcing tubes and/orreinforcing rods may be sized at the time of use by the physician. Ifdesired, a guidewire may be provided to facilitate introduction of theone or more reinforcing elements into the containment bag. Thisguidewire is preferably attached to the distal end of the containmentbag using an adhesive or other non-permanent attachment means. After theone or more reinforcement elements have been placed in the containmentbag, the guidewire can be detached from the containment bag by pullingor twisting the guidewire. Alternatively, the guidewire may beabsorbable, in which case it may be left in the patient at theconclusion of the procedure.

The seventh step is to introduce the injectable matrix material into thecontainment bag. Again this is done through the access hole previouslycreated.

In one preferred form of the invention, an injection tube is used todeliver the injectable matrix material into the containment bag underpressure, where it flows over and through the one or more reinforcementstructures contained within the containment bag. Suction may be usedduring the delivery of the injectable matrix material to aid in thewetting out of the reinforcement structures and removal of trapped air.The injection tube is withdrawn after the matrix material is injectedinto the containment bag. The injection tube is, preferably, alsocapable of transmitting an energy wave into the injectable matrixmaterial in cases where pulsatile flow or the application of vibrationalforces is required to aid injecting the matrix material into thecontainment bag.

The eighth step is to solidify the injectable matrix material so thatthe matrix material, the one or more reinforcing elements and thecontainment bag become a single solidified structure capable ofproviding support across the fracture line while the bone fractureheals.

The ninth step is to close the wound.

Thus it will be seen that the present invention comprises the provisionand use of a novel composite implant for treating bone fractures (and/orfor fortifying and augmenting a bone). The composite implant is disposedwithin the intramedullary canal of the bone (or within another openingin the bone) so as to function as a “splint”, whereby to carry thestress created during patient activity. This approach allows the bonefracture to heal (or provides fortification and/or augmentation of abone) with minimum inconvenience to the patient. The composite implantcomprises a plurality of components that are introduced sequentiallyinto the patient, and assembled in situ, thereby allowing the compositeimplant to be installed using a minimally invasive approach.Significantly, the properties of the composite implant can be customtailored for different treatment situations, e.g., the composite implantcan have different lengths and/or cross-sectional dimensions, thecomposite implant can have different mechanical properties, e.g.compressive and/or tensile strengths, etc., all according to theindividual needs of a particular patient.

In one preferred form of the present invention, there is provided acomposite implant comprising an injectable matrix material which isflowable and settable, and at least one reinforcing element forintegration with the injectable matrix material, the at least onereinforcing element adding sufficient strength to the injectable matrixmaterial such that when the composite implant is disposed in a cavity ina bone, the composite implant supports the bone.

In another preferred form of the present invention, there is provided amethod for treating a bone, the method comprising:

selecting at least one reinforcing element to be combined with aninjectable matrix material so as to together form a composite implantcapable of supporting the bone;

positioning the at least one reinforcing element in a cavity in thebone;

flowing the injectable matrix material into the cavity in the bone sothat the injectable matrix material interfaces with the at least onereinforcing element; and

transforming the injectable matrix material from a flowable state to anon-flowable state so as to establish a static structure for thecomposite implant, such that the composite implant supports the adjacentbone.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will bemore fully disclosed or rendered obvious by the following detaileddescription of the preferred embodiments of the invention, which is tobe considered together with the accompanying drawings wherein likenumbers refer to like parts, and further wherein:

FIGS. 1 and 2 are schematic views of a composite implant formed inaccordance with the present invention;

FIGS. 3 and 4 are schematic views of a concentric reinforcing tube thatmay be used to form the composite implant of FIGS. 1 and 2;

FIGS. 5 and 6 are schematic views of a rolled sheet that may be used toform the composite implant of FIGS. 1 and 2;

FIGS. 6A and 6B are schematic views showing how a flexible rolledreinforcing sheet may be radially compressed during delivery to thecontainment bag (FIG. 6A) and thereafter radially expanded (FIG. 6B)within the containment bag;

FIGS. 7 and 8 are schematic views of a flexible reinforcing rod that maybe used to form the composite implant of FIGS. 1 and 2;

FIGS. 8A, 8B, 8C and 8D are schematic views showing alternative forms ofthe flexible reinforcing rods of the present invention;

FIGS. 9-23 are schematic views showing a composite implant beingassembled in situ so as to treat a bone fracture;

FIGS. 24-26 show alternative forms of the composite implant of thepresent invention; and

FIG. 27 shows how the guidewire used to deliver the composite implantmay also be used to reduce a fracture and/or to help stabilize thefracture.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a new approach for treating bonefractures.

The present invention also provides a new approach for fortifying and/oraugmenting a bone.

Composite Implant

More particularly, the present invention comprises the provision and useof a novel composite implant for treating bone fractures and/or forfortifying and/or augmenting a bone. The composite implant is disposedwithin the intramedullary canal of a bone, or within another opening inthe bone, so as to function as an internal “splint”, whereby to carrythe stress created during patient activity. This allows a bone fractureto heal, or provides fortification and/or augmentation of a bone, withminimum inconvenience to the patient. The composite implant comprises aplurality of components that are introduced sequentially into thepatient, and assembled in-situ, wherein each of the components has asize and flexibility that allows it to be installed using a minimallyinvasive approach while collectively providing the required structuralreinforcement for the bone that is being treated. Significantly, theproperties of the composite implant can be custom tailored for differenttreatment situations, e.g., the composite implant can have differentlengths and/or different cross-sectional dimensions, the compositeimplant can have different compressive and/or tensile strengths, etc.,all according to the individual needs of a particular patient.

In one preferred form of the invention, and looking now at FIGS. 1 and2, the composite implant 5 comprises three components: a containment bag10, one or more reinforcing elements 15 and an injectable matrixmaterial 20.

Containment Bag

The containment bag 10 serves to protect the remaining components of thecomposite implant from the ingress of blood and/or other bodily fluidsthat might interfere with the deployment of the one or more reinforcingelements 15 and/or interfere with the deployment or solidification ofthe injectable matrix material 20. The containment bag 10 also serves toconstrain the flow of the injectable matrix material 20 while theinjectable matrix material 20 is in its injectable state. Thecontainment bag is flexible and may be fabricated from a resorbablepolymer such as a polyurethane, polylactic acid, glycolic acid or somemixture/copolymer thereof. Alternatively, the containment bag 10 may beformed from fibers that are woven, braided, knit, nonwoven, and/orotherwise worked so as to form a mesh bag. Suitable fibers includepolylactic acid, polyglycolic acid, polydioxanone or mixtures/copolymersthereof, bioresorbable and soluble glasses, and/or metal. In any case,the containment bag preferably has sufficient strength to allow theinjectable matrix material to be injected into the containment bag undersubstantial pressure so as to ensure good interfacial contact betweenthe injectable matrix material and the one or more reinforcing elements,the containment bag and the bone, and to minimize voids within thecontainment bag. Ideally the mesh bag is hydrophobic so as to minimizethe ingress of bodily fluids into the containment bag that may otherwiseinterfere with the deployment or solidification or accelerate thedegradation of the various components of the composite implant.Optionally, the mesh bag may have a limited porosity to allow someegress of the injectable matrix material 20 out of the containment bag,e.g., to osseointegrate with the surrounding bone. In this respect itshould be appreciated that such porosity may be varied across the extentof the containment bag so as to provide regions of greater or lesserporosity to the injectable matrix material 20, thus providing control ofthe ability of the injectable matrix material to infiltrate thesurrounding bone.

Reinforcing Elements

The one or more reinforcing elements 15 comprise (i) flexiblereinforcing sheets 22 (which are preferably in the form of concentrictubes such as is shown in FIGS. 3 and 4 or rolled sheets such as isshown in FIGS. 5 and 6), with the flexible reinforcing sheets 22comprising filaments 23 formed into a textile (i.e., woven, braided,knit, nonwoven, and/or otherwise worked so as to form the flexiblereinforcing sheets 22) or incorporated into a film so as to form theflexible reinforcing sheets 22, (ii) flexible reinforcing rods 35 (FIGS.7, 8, 8A, 8B, 8C and 8D), with the flexible reinforcing rods 35comprising a plurality of filaments 40 which are held together by anouter sheath 45 (FIGS. 7 and 8) of a textile or film (which may or maynot have the same composition and fiber orientation as theaforementioned flexible reinforcing sheets 22), or by a compacted (woundor compressed, etc.) connecting structure of a textile or film 45A(FIGS. 8A and 8B), or by a binder 46 (FIG. 8C) such as an adhesive, withor without surface projections 47 for improved integration withinjectable matrix material 20, (iii) particulates (e.g., particles,granules, segments, whiskers, nanotubes, nanorods, etc.), or (iv)combinations of the foregoing. Where the one or more reinforcingelements comprise flexible reinforcing sheets and/or flexiblereinforcing rods, the one or more reinforcing elements preferably havesufficient column strength to allow longitudinal delivery into thecontainment bag by pushing, and preferably have a configuration (e.g.,textured outer surfaces, tapered ends, etc.) to facilitate movement pastother reinforcing elements and/or intervening structures (e.g., catheterstructures). The one or more reinforcing elements preferably can beintroduced by means of a delivery catheter or sheath. Furthermore, wherethe one or more reinforcing elements comprise flexible reinforcingsheets (e.g., concentric tubes or rolled sheets) which are intended tobe radially compressed during delivery to facilitate passage through asmall opening (e.g., a catheter or surgical opening), the flexiblereinforcing sheets (e.g., concentric tubes or rolled sheets) maycomprise resilient elements 46 (e.g., resilient rings) to assist theirsubsequent return to an expanded state when positioned within thecontainment bag. The resilient elements may be thermosensitive or have ashape memory.

The filaments, fibers, and particulates used to form the aforementionedreinforcing elements may be biodegradable or bioabsorbable, ornon-biodegradable or non-bioabsorbable. By way of example but notlimitation, suitable biodegradable or bioabsorbable materials includepolyglycolide (PGA), glycolide copolymers, glycolide/lactide copolymers(PGA/PLA), glycolide/trimethylene carbonate copolymers (PGA/TMC),stereoisomers and copolymers of polylactide, poly-L-lactide (PLLA),poly-D-lactide (PDLA), poly-DL-lactide (PDLLA), L-lactide, DL-lactidecopolymers, L-lactide, D-lactide copolymers, lactide tetramethyleneglycolide copolymers, lactide/trimethylene carbonate copolymers,lactide/delta-valerolactone copolymers, lactide/epsilon-caprolactonecopolymers, polydepsipeptide (glycine-DL-lactide copolymer),polylactide/ethylene oxide copolymers, asymmetrically 3,6-substitutedpoly-1,4-dioxane-2,4-diones, poly-βhydroxybutyrate (PHBA),PHBA/beta-hydroxyvalerate copolymers (PHBA/PHVA),poly-beta.-hydroxypropionate (PHPA), poly-beta-dioxanone (PDS),poly-DELTA-valerolactone, poly-DELTA-caprolactone, methylmethacrylate-N-vinyl pyrrolidone copolymers, polyester amides, oxalicacid polyesters, polydihydropyrans, polypeptides from alpha-amino acids,poly-beta-maleic acid (PMLA), poly-beta-alkanoic acids, polyethyleneoxide (PEO), silk , collagen, derivatized hyaluronic acid resorbable orsoluble glasses, resorbable ceramic, resorbable metal and chitinpolymers. By way of further example but not limitation, suitablenon-biodegradable or non-bioabsorbable materials include polyolefins,polyamides, polyesters and polyimides, polyetheretherketone (PEEK),glass, ceramic, metal, and carbon fiber.

As will hereinafter be discussed, the one or more reinforcing elements15 are selected by the physician so as to provide the composite implantwith the desired size and mechanical properties, e.g. stiffness andstrength. Thus, and as will hereinafter be discussed, the physician mayselect from a variety of different reinforcing elements, each having aparticular composition and length, and preferably deliver thosereinforcing elements sequentially to the patient, whereby to provide thecomposite implant with the desired size and attributes of stiffness andstrength.

In one preferred form of the invention, the one or more reinforcingelements 15 comprise from about 5% to 95% (by volume) of the compositeimplant, typically at least 20% (by volume) of the composite implant.

In another embodiment, the reinforcing properties of the one or morereinforcing elements 15 may be modified by changing the materials,dimensions, shape, and surface characteristics of the fibers, filaments,and particulates.

In another embodiment, the reinforcing properties of the one or morereinforcing elements 15 may be modified by changing the orientation,volume, twist, and angle of the fibers and filaments within thereinforcing elements. In preferred constructions, the fibers andfilaments are typically set at an acute angle to intersecting fibers andfilaments in order to strengthen the reinforcing structure, but theangle may be any angle between 0 degrees and 90 degrees.

In another embodiment, the properties of the composite implant may bemodified by changing the orientation of one or more of the reinforcingelements 15, and/or by changing the volume of one or more of thereinforcing elements 15.

It will be appreciated that the properties of the composite implant maybe modified by changing the layup or selection of one or more of thereinforcing elements 15.

It will also be appreciated that the reinforcing properties, anddegradation profiles, of the one or more reinforcing elements 15 may bemodified by changing the material, dimensions, shape, orientation,volume, and surface features of the fibers, filaments, and/orparticulates used to form the one or more reinforcing elements 15.

Where the reinforcement elements comprise a textile, its reinforcingproperties and degradation profile may be modified by changing thematerials, orientation, length, shape, volume, twist, and angle of thefibers and filaments within the textile of the reinforcing elements. Thefibers and filaments in a textile of a reinforcing element arepreferably set at an acute angle to intersecting fibers and filaments,but the angle may vary between 0 degrees and 90 degrees or random.

Compatibility among the specific components that comprise a compositestructure is essential in order to ensure optimal interfacial bonding,mechanical properties, physical properties, and osseointegration.Compounds known as coupling agents or compatibilizers, which may beincorporated into the components of the composite implant, serve toenhance the chemical bonding between the specific components of thecomposite implant. In a preferred embodiment, the interfacial bondstrength between the containment bag, reinforcing elements, injectablematrix material, and bone can be enhanced through the addition of avariety of compatibilizers, e.g., calcium phosphate, hydroxyapatite,calcium apatite, fused-silica, aluminum oxide, apatite-wollastoniteglass, bioglass, compounds of calcium salt, phosphorus, sodium salt andsilicates, maleic anhydride, diisocyanate, epoxides, silane, andcellulose esters. These agents may be incorporated into, and/or appliedto, the components of the composite implant through a number of methods,e.g., plasma deposition, chemical vapor deposition, dip coating,melt-blending, spin or spray-on. A specific example is the applicationof a silane coupling agent to glass fiber reinforcement in order toincrease its interfacial bonding strength with the injectable matrixmaterial. Another example is the vapor deposition of calcium phosphateonto the surface of the containment bag such that the bonding betweenthe injectable matrix material and the containment bag is enhanced. Inorder to increase the compatibility between the containment bag and bonethat it is supporting, dip-coating the exterior of the containment bagwith an osseoconductive material (such as fused-silica with aluminumoxide) will improve their adhesion to each other and accelerateosseointegration.

Those skilled in the art will recognize still other ways to modify theproperties of the composite implant in view of the present disclosure.

Injectable Matrix Material

The injectable matrix material 20 is preferably polymeric and ispreferably biodegradable. The injectable matrix material 20 is designedto be polymerized in situ. The matrix material is preferably amulti-component polymer system that is mixed immediately prior tointroduction into the patient. Optionally, the injectable matrixmaterial 20 may contain a biocompatible solvent, with the solventreducing viscosity so as to allow the matrix material to be injected,and with the solvent thereafter rapidly diffusing from the compositeimplant so as to facilitate or provide stiffening of the compositeimplant 5. The solvent may also be used to alter the porosity of theinjectable matrix material 20.

In a preferred embodiment of the present invention, polyurethanes areutilized as the injectable matrix material, although other suitablechemistry systems will be apparent to those skilled in the art. Thepolyurethanes are produced through the reaction of a difunctional ormultifunctional isocyanate with a difunctional or multifunctionalcompound containing an active hydrogen, including water, hydroxylmaterials and amines.

Suitable isocyanates useful in the practice of this invention include,but are not limited to, aromatic diisocyanates such as 2,4-toluenediisocyanate, 2,6-toluene diisocyanate, 2,2′-diphenylmethanediisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethanediisocyanate, diphenyldimethylmethane diisocyanate, dibenzyldiisocyanate, naphthylene diisocyanate, phenylene diisocyanate, xylylenediisocyanate, 4,4′-oxybis(phenylisocyanate) or tetramethylxylylenediisocyanate; aliphatic diisocyanates such as tetramethylenediisocyanate, hexamethylene diisocyanate, dimethyl diisocyanate, lysinediisocyanate, 2-methylpentane-1,5-diisocyanate,3-methylpentane-1,5-diisocyanate or 2,2,4-trimethylhexamethylenediisocyanate; and alicyclic diisocyanates such as isophoronediisocyanate, cyclohexane diisocyanate, hydrogenated xylylenediisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenatedtrimethylxylylene diisocyanate, 2,4,6-trimethyl 1,3-phenylenediisocyanate.

The present invention comprises the use of these same multi-functionalisocyanates with multifunctional amines or multifunctional substitutedamines, multifunctional ketimines, multifunctional aldimines,isocyanurates or biurets. By way of example but not limitation, suchmultifunctional amines may include hexamethylene diamine, isophoronediamine, and lysine. Examples of substituted amines may includeN-substituted diaspartic acid derivatives. Examples of multifunctionalketimines and aldimines may be made from the multifunctional aminesmentioned previously and methyl isobutyl ketone or isobutyraldehyde.

When a non-biodegradable implant is desired, the aromatic isocyanatesare generally favored. When a biodegradable implant is desired, thealiphatic isocyanates are generally favored. In an embodiment of thisinvention, the aliphatic isocyanates are preferred.

In a preferred embodiment of this invention, the isocyanate component isreacted with a polyol to produce a polyurethane. Suitable polyolsinclude, but not limited to, polycaprolactone diol and polycaprolactonetriol. Suitable dihydroxy compounds which may be utilized in thepractice of this invention include, but are not limited to, ethyleneglycol, propylene glycol, butylene glycol, hexylene glycol and polyolsincluding polyalkylene oxides, polyvinyl alcohols, and the like. In someembodiments, the polyol compounds can be a polyalkylene oxide such aspolyethylene oxide (“PEO”), polypropylene oxide (“PPO”), block or randomcopolymers of polyethylene oxide (PEO) and polypropylene oxide (PPO).Higher functional polyol compounds are also useful and can includeglycerin, 1,2,4-butanetriol, trimethylol propane, pentaerythritol anddipentaerythritol, 1,1,4,4-tetrakis(hydroxymethyl)cyclohexane. Otheruseful polyols can include triethanol amine andN,N,N′,N′-Tetrakis(2-hydroxyethyl)ethylenediamine.

The polyol materials discussed above may be used alone or, optionally,as mixtures thereof. The foregoing materials are merely examples ofuseful components for producing polyurethanes and should not be viewedas a limitation of the present invention. These higher functional polyolmaterials will produce highly crosslinked polyurethanes with highhardness and stiffness.

In preferred embodiments, the multifunctional hydroxyl material mayinclude at least one bioabsorbable group to alter the degradationprofile of the resulting branched, functionalized compound.Bioabsorbable groups which may be combined with the multifunctionalcompound include, but are not limited to, groups derived from glycolide,glycolic acid, lactide, lactic acid, caprolactone, dioxanone,trimethylene carbonate, and combinations thereof. For example, in oneembodiment, the multifunctional compound may include trimethylol propanein combination with dioxanone and glycolide. Methods for addingbioabsorbable groups to a multifunctional compound are known in the art.Where the multifunctional compound is modified to include bioabsorbablegroups, the bioabsorbable groups may be present in an amount rangingfrom about 50 percent to about 95 percent of the combined weight of themultifunctional compound and bioabsorbable groups, typically from about7 percent to about 90 percent of the combined weight of themultifunctional compound and bioabsorbable groups.

The multifunctional compound can have a weight (average molecularweight) ranging from about 50 to about 50000, typically from about 100to about 3000, and typically possesses a functionality ranging fromabout 2 to about 6.

In a preferred embodiment, the polycaprolactone diols and triols providepolyurethanes that are biodegradable.

The isocyanate is reacted with a polyol to produce a prepolymer. Methodsfor endcapping the polyol with an isocyanate are known to those skilledin the art. For example, a polycaprolactone diol may be combined withisophorone diisocyanate by heating to a suitable temperature rangingfrom about 55 degrees C. to about 80 degrees C., typically about 70degrees C. The resulting diisocyanate-functional compound may then bestored until combined with additional polyol to form the finalpolyurethane product.

Reaction of the urethane prepolymer with polyol to form the finalpolyurethane product generally requires a catalyst to provide convenientworking and cure times. Polyurethane catalysts can be classified intotwo broad categories, amine compounds and organometallic complexes. Theycan be further classified as to their specificity, balance, and relativepower or efficiency. Traditional amine catalysts have been tertiaryamines such as triethylenediamine (TEDA, also known as1,4-diazabicyclo[2.2.2]octane or DABCO, an Air Products's trademark),dimethylcyclohexylamine (DMCHA), and dimethylethanolamine (DMEA).Tertiary amine catalysts are selected based on whether they drive theurethane (polyol+isocyanate, or gel) reaction, the urea(water+isocyanate, or blow) reaction, or the isocyanate trimerizationreaction (e.g., using potassium acetate, to form isocyanurate ringstructure). Since most tertiary amine catalysts will drive all threereactions to some extent, they are also selected based on how much theyfavor one reaction over another.

Another useful class of polyurethane catalysts are the organometalliccompounds based on mercury, lead, tin (dibutyl tin dilaurate), bismuth(bismuth octanoate), titanium complexes and zinc. Dibutyl tin dilaurateis a widely used catalyst in many polyurethane formulations. Stannousoctoate is another catalyst that may be used.

In the practice of this invention dibutyl tin dilaurate is a favoredcatalyst at concentrations below 0.5% and more preferably atconcentrations below 0.2% by weight.

Additions To Injectable Matrix Material

If desired, the injectable matrix material 20 may also comprise abioactive filler material, a therapeutic agent, and/or an agent toenhance visibility while imaging the composite implant.

Fillers. The injectable matrix material may include a filler in the formof biocompatible and or osteoconductive particles. The first or primaryfiller, preferably in the form of particles, may also provide porosity,bone ingrowth surfaces and enhanced permeability or pore connectivity.One suitable particulate filler material is tricalcium phosphate,although other suitable filler materials will be apparent to thoseskilled in the art such as orthophosphates, monocalcium phosphates,dicalcium phosphates, tricalcium phosphates, tetracalcium phosphates,amorphous calcium phosphates and combinations thereof. Alsobiodegradable glasses can be utilized as a filler.

The filler particles may comprise a degradable polymer such aspolylactic acid, polyglycolic acid, polycaprolactone and co-polymersthereof. The particles may also comprise degradable polymer containingone or more inorganic fillers.

In one embodiment the inorganic filler particles have mean diametersranging from about 1 micron to about 20 microns.

In another embodiment the porosity and compressive properties of thematrix material may be modified by using additional fillers that may beinorganic, organic or another suitable biocompatible material. Suchrefinements include the addition of particles having mean diametersranging from about 10 microns to about 500 microns or a mean diameter ofless than 1 micron. In certain matrix materials the additional fillermaterials may be provided in one or more size distributions.

The composite implant can become porous after implantation so as to aidthe resorption and bone healing process. This porosity can be generatedby various mechanisms including the preferential resorption of filler,such as calcium sulfate or

α-tricalcium phosphate, bioglass or of a polymeric component.Alternatively, the formulation can include a biocompatible solvent suchas DMSO that is leached out of the implant post implantation. The poresare preferably 100 μm in diameter with interconnectivity to allow boneingrowth.

The composite implant may also include an additional porogen. In oneform of the invention, the porogen is sugar or a polysaccharide, such asdextran, but other biocompatible porogens will be apparent to thoseskilled in the art such as crystalline materials in the form of solublesalts.

In another embodiment of the present invention, the filler, eitherinorganic or polymeric, may be present in combined amount ranging fromabout 10 to about 50 wt % of the matrix composition. In certain cases itmay be desirable to have the filler content over 50 wt %. If a porogenis added, it will preferably be present in an amount ranging from about15 to about 50 wt %.

Compatibilizing agents may also be included.

Therpeutics Agents. The inclusion of a therapeutic agent in theinjectable matrix material, or in one or more of the reinforcingelements, is contemplated in the practice of this invention. Therapeuticagents can include agents that promote bone formation, or for relief ofpain. Agents may include, but are not limited to, parathyroid hormone,vitamin D, calcitonin, calcium, PO4, non-steroidal anti-inflammatorydrugs (NSAIDS) such as, but not limited to, acetaminophen, salicylates(aspirin, diflunisal, salsalate), acetic acid derivatives (indomethacin,ketorolac, sulindac etodolac, diclofenac, nabumetone), propionic acidderivatives (ibuprofen, naproxen, flurbiprofen, ketoprofen, oxaprozin,fenoprofen, loxoprofen), fenamic acid derivatives (meclofenamic acid,mefenamic acid, flufenamic acid, tolfenamic acid), oxicam (enolic acid)derivatives (piroxicam, meloxicam, tenoxicam, droxicam, lornoxicam,isoxicam), arylalkanoic acid derivatives (tolmetin); selective COX-2inhibitors (celecoxib, rofecoxib, valdecoxib, parecoxib, lumiracoxib,etoricoxib, firocoxib); steroids such as, but not limited to,corticosteroids (hydrocortisone, hydrocortisone acetate, cortisoneacetate, tixocortol pivalate, prednisolone, methylprednisolone,prednisone, triamcinolone acetonide, triamcinolone alcohol, mometasone,amcinonide, budesonide, desonide, fluocinonide, fluocinolone acetonide,halcinonide, betamethasone, dexamethasone, fluocortolone,hydrocortisone-17-valerate, aclometasone dipropionate, betamethasonevalerate, betamethasone dipropionate, prednicarbate,clobetasone-17-butyrate, clobetasol-17-propionate, fluocortolonecaproate, fluocortolone pivalate, or fluprednidene acetate); immuneselective anti-inflammatory derivatives (ImSAIDs) such as, but notlimited to, submandibular gland peptide T (SGp-T) and derivativesphenylalanine-glutamine-glycine (FEG) and its D-isomeric form (feG);narcotic compositions such as, but not limited to, buprenorphine,butorphanol, codeine, hydrocodone, hydromorphone, levorphail,meperidine, methadone, morphine, nalbuphine, oxycodone, oxymorphone,pentaxocine, or propoxyphene; other analgesic compositions such as, butnot limited to, tramadol, or capsaicin; local anethetics (includingshort term acting anesthetics) such as, but not limited to, benzocaine,dibucaine, lidocaine, or prilocaine; bisphosphonates, or combinations ofany of the above.

Therapeutic agents delivered locally can use a carrier vehicle toprovide a protective environment, provide target delivery to cells orwithin cells, provide locally delivery, timed delivery, staged deliveryand/or use delivery technology know in the art.

The therapeutic agents can also include bone growth activating factors,such as bone morphogenetic proteins (BMPs), FGF (fibroblast growthfactor), VEGF (vascular endothelial growth factor), PDGF (plateletderived growth factor), or PGE2 (prostaglandin E2). Bone morphogeneticproteins can include BMP1, BMP2, BMP3, BMP4, BMP5, BMP6, BMP7, BMP8a,BMP8b, BMP10, or BMP15.

Agent To Enhance Visibility. It is also possible for the injectablematrix material to include one or more particles or liquid agents toenhance visibility while imaging the composite implant. By way ofexample but not limitation, where the physician may be using fluoroscopyto view the bone being treated and the composite implant, the injectablematrix material may include bismuth oxychloride, bismuth subcarbonate,barium, barium sulfate, ethiodol, tantalum, titanium dioxide,tantalumpentoxide, tungsten, strontium carbonate, strontium halidesplatinum, titanium, silver, gold, palladium, iridium, osmium, copper,niobium, molybdenum, strontium, strontium salts and gallium, iodinesubstituted compounds/polymers, and/or alloys such as nickel-titanium,nickel-manganese-gallium, platinum-iridium, platinum-osmium to enhancethe visibility of the injectable matrix material under fluoroscopy.

Preferred Method Of Use

The composite implant 5 is disposed within the intramedullary canal of abone, or within another opening in the bone, so as to function as aninternal “splint”, whereby to carry the stress created during patientactivity. This allows a bone fracture to heal, or provides fortificationand/or augmentation of bone, with minimum inconvenience to the patient.The components of the composite implant 5 are introduced sequentiallyinto the patient, and assembled in-situ, thereby allowing the compositeimplant 5 to be installed using a minimally invasive approach.

By way of example but not limitation, the composite implant 5 may beused in the following manner to treat a fracture in the tibia.

Looking now at FIG. 9, the first step is to create an access hole 50into the bone that is to be treated. If desired, an access port 52 maybe disposed in access hole 50 so as to facilitate delivering elementsthrough access hole 50. When treating fractures in long bones, the holeis made into the intramedullary canal distal to, or proximal to, thefracture site. Significantly, the modular nature of the compositeimplant means that the composite implant can be introduced into theintramedullary canal of the bone that is to be treated through an accesshole that is smaller than the final form of the composite implant. Forexample, in the case of where the composite implant is to fill anintramedullary canal that is 10 mm in diameter, the required access holemay be only 3 mm in diameter. As a result, the composite implant may bedeployed using a minimally invasive procedure that may be carried out inan office setting or surgicenter setting rather than in a conventionaloperating room. Access hole 50 is preferably drilled at an acute angleto the bone which is being treated, e.g., at an angle of approximately45 degrees, but it may be drilled at an angle anywhere between 0 degreesand 90 degrees, either proximal or distal to the fracture. This allowsthe components of the composite implant to be more easily introducedinto the intramedullary canal.

The second step is to remove or harvest the bone marrow (and/or othermatter) in the intramedullary canal, and to clean the intramedullarycanal, so as to provide a space for the composite implant 5. This isdone through the access hole 50 previously created. In one preferredform of the invention, and looking now at FIG. 10, the device forremoving or harvesting of the bone marrow from the intramedullary canalcomprises a catheter 55 with provision for introducing a liquid or gasinto the intramedullary canal and suction for removal of material fromthe intramedullary canal. The liquid or gas can be used to disrupt thecontent in the intramedullary canal or prepare the intramedullary canalfor a composite implant. The liquid or gas can be introduced in acontinuous, pulsed, or intermittent flow. A rotatable flexible rod 60,with a shaped end or attachment at the distal end (e.g., having one ormore wire loops, brushes, cutting tips, etc., which may or may not bemade out of a shape memory material such as Nitinol, and which may ormay not be steerable), is optionally used to disrupt the bone marrow inthe intramedullary canal so as to aid in the removal of the bone marrow.When harvest of the bone marrow is required, a tissue trap is utilized.FIG. 11 shows the intramedullary canal of the bone after it has beenappropriately prepared.

Looking next at FIG. 12, the third step, if needed, is to place a flowrestrictor plug 65 in the intramedullary canal distal to, and/orproximal to, where the composite implant 5 will be placed in theintramedullary canal. Again, this is done through the access hole 50previously created. Where two flow restrictor plugs 65 are used, the twoflow restrictor plugs may be connected to one another. The flowrestrictor plugs 65 may be optionally placed prior to removing orharvesting the bone marrow.

The fourth step, if needed, is to return the bone to proper alignment.

The fifth step is to introduce the containment bag 10 into theintramedullary canal via the access hole 50 previously created. In onepreferred form of the invention, and looking now at FIG. 13, thecontainment bag 10 is introduced into the intramedullary canal through adelivery catheter 70, and is releasably attached to a catheter that isused for subsequent delivery of the remaining components of thecomposite implant, i.e., the one or more reinforcement elements 15 andthe injectable matrix material 20. The catheter may have markers on itsexterior surface so as to allow the physician to determine the positionof the containment bag 10 within the bone by direct visualization of themarkers on the exterior surface of the catheter. Alternatively, and/oradditionally, containment bag 10 may have markers thereon so as to allowthe physician to determine the position of the containment bag 10 withinthe bone by indirect visualization (e.g., fluoroscopy, CT, etc.). Notethat the flexible (and compressible) nature of the containment bag 10facilitates its delivery into the intramedullary canal via a minimallyinvasive approach (i.e., via the access hole 50 previously created). Thecontainment bag 10 may comprise an auxiliary channel to allow monitoringand control of subsequent pressurization with the injectable matrixmaterial. This auxiliary channel may be parallel to the deliverycatheter, or inside the delivery catheter, or the auxiliary channel maybe at the distal end of the containment bag. Alternatively, there may bea valve at the distal end of the containment bag, or at other strategicregions of the containment bag, that can limit pressure within thecontainment bag. FIG. 14 shows containment bag 10 disposed within theintramedullary canal of the bone.

The sixth step is to sequentially introduce the one or more reinforcingelements 15 into the containment bag 10. This is done through the accesshole 50 previously created. Note that the flexible nature of thereinforcing elements 15 facilitates their delivery into the containmentbag 10 via the access hole 50 previously created. The one or morereinforcing structures 15 are preferably introduced into the containmentbag sequentially so as to build up a reinforcing mass. In one preferredform of the invention, and looking now at FIGS. 15 and 16, a pluralityof flexible reinforcing sheets 22 (in the form of concentric reinforcingtubes) are sequentially inserted into the containment bag 10, with oneflexible reinforcing concentric tube 22 being nested inside another, anda plurality of flexible reinforcing rods 35 are sequentially insertedwithin the innermost flexible concentric reinforcing tube 22 (FIGS.17-19). In one preferred form of the invention, the flexible reinforcingsheets 22 (which are preferably in the form of concentric tubes such asis shown in FIGS. 3 and 4 or rolled sheets such as is shown in FIGS. 5and 6) are delivered to the interior of the containment bag by pushingthem out of a delivery tube or, alternatively, by carrying them into thecontainment bag while held within a delivery tube and then retractingthe delivery tube, whereby to expose the flexible reinforcing sheets andallow them to expand. Preferably the size and number of flexibleconcentric reinforcing tubes 22 and reinforcing rods 35 are selected soas to meet the individual needs of a particular patient. The number offlexible concentric reinforcing tubes 22 utilized in the compositeimplant, and/or their lengths and/or cross-sectional dimensions, and/orthe number of reinforcing rods 35 used, and/or their lengths and/orcross-sectional dimensions, may be selected according to the individualneeds of a particular patient. Preferably the number, length, andcross-sectional dimensions of the reinforcing tubes, and the number,length, and cross-sectional dimensions of the reinforcing rods, areselected so as to provide a composite implant having variable stiffnessalong its length, e.g., a composite implant having a stiffer centralregion (e.g., 20 GPa) and less stiff distal and proximal ends (e.g., 3GPa), whereby to prevent stress risers from being created at the ends ofthe composite implant. To this end, the reinforcing tubes, and thereinforcing rods, are preferably provided in a variety of sizes forappropriate selection by the physician; alternatively, the reinforcingtubes and/or reinforcing rods may be sized at the time of use by thephysician. If desired, a guidewire 75 may be provided to facilitateintroduction of the one or more reinforcing elements into thecontainment bag. This guidewire 75 is preferably attached to the distalend of the containment bag 10 using an adhesive or other non-permanentattachment means. After the one or more reinforcement elements 15 havebeen placed in the containment bag, the guidewire 75 can be detachedfrom the containment bag 10 by pulling or twisting the guidewire.Alternatively, the guidewire 75 may be absorbable, in which case it maybe left in the patient at the conclusion of the procedure.

The seventh step is to introduce the injectable matrix material 20 intothe containment bag. Again this is done through the access hole 50previously created. In a preferred form of the invention the injectablematrix material is formed from two or more components that are mixedimmediately prior to injection into the patient. This may occur throughuse of a static mixer fed by multiple syringes. Alternatively thecomponents may be mixed in a bowl and then loaded into a syringe that isconnected to the injection tube. In one preferred form of the invention,and looking now at FIGS. 20 and 21, an injection tube 80 is used todeliver the injectable matrix material 20 into the containment bag 10under pressure, where it flows over and through the one or morereinforcement structures 15 contained within the containment bag 10. Theinjection tube 80 is withdrawn after the matrix material is injectedinto the containment bag. The injection tube is, preferably, alsocapable of transmitting an energy wave into the injectable matrixmaterial in cases where pulsatile flow or the application of vibrationalforces is required to aid injecting the matrix material into thecontainment bag. Suction may be used to facilitate wetting out of thereinforcement structures by removal of trapped air from the composite.

The eighth step is for the injectable matrix material to solidify sothat the matrix material 20, the one or more reinforcing elements 15 andthe containment bag 10 become a single solidified structure 5 (FIGS. 22and 23) capable of providing support across the fracture line while thebone fracture heals. If desired, an expandable device (e.g., a balloon)may be used to provide a radial force to aid in the creation of a singleintegrated structure. More particularly, the expandable device (e.g.,balloon) may be used to enhance the penetration of the injectable matrixmaterial into and between one or more reinforcing elements, thecontainment bag and the bone, and to enhance the interfacial bondbetween the injectable matrix material and the one or more reinforcingelements, between the injectable matrix material and the containmentbag, and between the injectable matrix material and the bone. In thepreferred embodiments of the invention this solidification occursthrough a chemical reaction that proceeds at a rate that allowssufficient time for injection before the viscosity increases to a pointwhere injection is not possible. Generally this time is five to tenminutes. The solidification occurs within thirty to sixty minutes,although with most chemistries there will be a continuation in strengthbuild-up over a period of hours. In the preferred chemistries theexothermic nature of the reaction is limited to minimize temperatureincrease in the matrix material to less than 10 degrees C.

Note how, in FIGS. 22 and 23, the composite implant can contour asneeded to the geometry of the intramedullary canal of the bone, i.e., inFIG. 22 the composite implant has a substantially linear shape to matchthe substantially linear shape of the intramedullary canal of the tibia,whereas in FIG. 23 the composite implant has a contoured shape to matchthe contour of the clavicle.

The ninth step is to close the wound.

Thus it will be seen that the present invention comprises the provisionand use of a novel composite implant for treating bone fractures (and/orfor fortifying and augmenting a bone). The composite implant is disposedwithin the intramedullary canal of the bone (or within another openingin the bone) so as to function as a “splint”, whereby to carry thestress created during patient activity. This approach allows the bonefracture to heal (or provides fortification and/or augmentation of abone) with minimum inconvenience to the patient. The composite implantcomprises a plurality of components that are introduced sequentiallyinto the patient, and assembled in situ, thereby allowing the compositeimplant to be installed using a minimally invasive approach.Significantly, the properties of the composite implant can be customtailored for different treatment situations, e.g., the composite implantcan have different lengths and/or cross-sectional dimensions, thecomposite implant can have different compressive and/or tensilestrengths, etc., all according to the individual needs of a particularpatient.

Additional Constructions

It should be appreciated that, if desired, containment bag 10 may beomitted. In this case, the one or more reinforcing elements 15 andinjectable matrix material 20 are deployed directly into theintramedullary canal (or other opening) in the bone that is beingtreated, without an intervening containment bag 10.

Furthermore, it should be appreciated that, if desired, compositeimplant 5 may be formed out of flexible reinforcing sheets 22 withoutany flexible reinforcing rods 35 (FIG. 24); with flexible reinforcingrods 35 and without any flexible reinforcing sheets 22 (FIG. 25); andwith a laminated construction comprising both flexible reinforcingsheets 22 and flexible reinforcing rods 35 (FIG. 26).

In addition, FIG. 27 shows how guidewire 75 may be used to reduce afracture prior to delivery of the composite implant. More particularly,in this form of the invention, guidewire 75 has an enlargement 85 formedat one end, with enlargement 85 being disposed exterior to the bonebeing treated, and with the opposite end 90 of guidewire 75 emergingfrom port 52. As a result of this configuration, by applying tension toend 90 of guidewire 75, the fracture can be reduced and the tensionedguidewire 75 can help support the bone. In one preferred form of theinvention, a fixture 95 may be positioned within the intramedullarycanal of the bone, adjacent to enlargement 85, so as to direct guidewire75 along the longitudinal channel of the bone and thereby facilitatefracture reduction and delivery of the composite.

EXAMPLES Example 1

Preparation of 50/50 prepolymer: 10.60 g polycaprolactone diol (0.02mol), 6.00 g polycaprolactone triol (0.02 mol), both previously vacuumdried and 23.31 mL isophorone diisocyanate (0.10 mol) were stirredcontinuously while heating slowly to 70° C., and then stirred at 70° C.for 2 hours. The heat and stirring was stopped and the reaction wasallowed to sit at room temperature overnight. Yield ˜40 g clear highlyviscous material.

Example 2

Preparation of 60/40 prepolymer: 15.90 gl polycaprolactone diol (0.03mol), 6.00 g polycaprolactone triol (0.02 mol), both previously vacuumdried and 27.97 mL isophorone diisocyanate (0.13 mol) were stirredcontinuously while heating slowly to 70° C., and then stirred at 70° C.for 2 hours. The heat and stirring was stopped and the reaction wasallowed to sit at room temperature overnight. Yield ˜50 g clear viscousmaterial.

Example 3

Preparation of hexamethylenediamine aspartic acid ester: 11.62 ghexamethylenediamine (0.10 mol) and 38.86 g tert-butanol was combined,and 34.46 g diethyl maleate (0.20 mol) was added slowly. Reaction was N₂blanketed and heated to 70° C. with stirring for 30 minutes. Reactionwas allowed to sit at room temperature for 120 hours before removingtert-butanol via rotary evaporation at 70° C. and 215-195 mbar. Yield˜45 mL clear slightly viscous liquid.

Example 4

Preparation of isophorone diamine aspartic acid ester: 17.04 gisophorone diamine (0.10 mol) and 38.75 g tert-butanol was combined, and34.43 g diethyl maleate (0.20 mol) was added slowly. Reaction was N₂blanketed and heated to 35° C. with stirring for 15 minutes. Reactionwas allowed to sit at room temperature for 120 hours before removingtert-butanol via rotary evaporation at 70° C. and 215-195 mbar. Yield˜45 mL clear slightly viscous liquid.

Example 5

Preparation of diethylenetriamine aspartic acid ester: 10.33 gdiethylenetriamine (0.10 mol) and 38.74 g tert-butanol was combined, and34.36 g diethyl maleate (0.20 mol) was added slowly. Reaction was N₂blanketed and heated to 35° C. with stirring for 10 minutes. Reactionwas allowed to sit at room temperature for 120 hours before removingtert-butanol via rotary evaporation at 70° C. and 215-195 mbar. Yield˜35 mL pale yellow slightly viscous liquid.

Example 6

Preparation of Polypropylene braid: A Steeger horizontal braider wasused with 0.008″ OD polypropylene monofilament. Braids were run with 24sheath yarns, and the samples that were run with axials had 12 axials,all made of the same 0.008″ OD PP. Samples were run over 5 mm and 10 mmdiameter mandrels.

Example 7

Preparation of Polylactic acid (PLA) braid: A Steeger horizontal braiderwas used with 120d PLLA multifilament. Braids were run with 48 ends, andthe samples that were run with axials had 24 axials, all made of thesame 120d PLLA. Samples were run over 5, 7 and 10 mm diameter mandrels.

Example 8

Preparation of 1.5 mm diameter PLA braid: 1.5 mm braids were constructedaround a core constructed of 90 ends of 75d PLLA, twisted atapproximately 2 TPI. The outer sheath was constructed of 24 ends of 120dPLLA. A Steeger 48 end horizontal braider was used.

Example 9

Preparation of 1.5 mm diameter PLA braid with axial fibers: 1.5 mmbraids were constructed around a core constructed of 90 ends of 75dPLLA, twisted at approximately 2 TPI. The outer sheath was constructedof 24 ends of 120d PLLA, and 12 axial ends of 120d PLLA. A Steeger 48end horizontal braider was used.

Example 10

Preparation of Polyurethane: 2.60 grams of the prepolymer of Example 1was mixed with 0.30 grams of polycaprolactone triol and 0.10 grams ofglycerol at 0.13% w/w dibutyltin dilaurate. The mixture was transferredinto a 3m1 syringe and placed in an oven at 37° C. to cure overnight.The sample was removed from the syringe and cut using a diamond saw tomake a compression test piece. Compression testing showed that thematerial had a compressive stiffness of 1.1 GPa and a yield strength of56 MPa.

Example 11

Preparation of Polyurethane: 2.60 grams of the prepolymer of Example 1was mixed with 1.00 grams of tricalcium phosphate and 0.30 grams ofpolycaprolactone triol and 0.10 grams of glycerol at 0.13% w/wdibutyltin dilaurate. The mixture was transferred into a 3 ml syringeand placed in an oven at 37° C. to cure overnight. The sample wasremoved from the syringe and cut using a diamond saw to make acompression test piece. Compression testing showed that the material hada compressive stiffness of 1.3 GPa and a yield strength of 63 MPa.

Example 12

Preparation of Polyurethane: 2.60 grams of the prepolymer of Example 1was mixed with 2.48 grams of tricalcium phosphate and 0.35 grams ofpolycaprolactone triol and 0.10 grams of glycerol 0.13% w/w dibutyltindilaurate. The mixture was transferred into a 3 ml syringe and placed inan oven at 37° C. to cure overnight. The sample was removed from thesyringe and cut using a diamond saw to make a compression test piece.Compression testing showed that the material had a compressive stiffnessof 1.8 GPa and a yield strength of 71 MPa.

Example 13

Preparation of Polyurethane: 4.05 grams of the prepolymer of Example 2was mixed with 0.50 grams of polycaprolactone triol and 0.15 grams ofglycerol 0.13% w/w dibutyltin dilaurate. The mixture was transferredinto a 3 ml syringe and placed in an oven at 37° C. to cure overnight.The sample was removed from the syringe and cut using a diamond saw tomake a compression test piece. Compression testing showed that thematerial had a compressive stiffness of 1.1 GPa and a yield strength of53 MPa.

Example 14

Preparation of Polyurethane: 4.05 grams of the prepolymer of Example 2was mixed with 2.01 grams of tricalcium phosphate and 0.50 grams ofpolycaprolactone triol and 0.15 grams of glycerol 0.13% w/w dibutyltindilaurate. The mixture was transferred into a 3 ml syringe and placed inan oven at 37° C. to cure overnight. The sample was removed from thesyringe and cut using a diamond saw to make a compression test piece.Compression testing showed that the material had a compressive stiffnessof 1.5 GPa and a yield strength of 69 MPa.

Example 17

Preparation of Polyurethane: 5.26 grams of the prepolymer of Example 1was mixed with 3.81 grams of the aspartic acid ester from Example 5. Themixture was transferred to a 3 ml syringe and placed in an oven at 37°C. to cure overnight. The sample was removed from the syringe and cutusing a diamond saw to make a compression test piece. Compressiontesting showed that the material had a compressive stiffness of 0.6 GPaand a yield strength of 29 MPa.

Example 18

Preparation of Polyurethane: 2.05 grams of the prepolymer of Example 2was mixed with 2.17 grams of the aspartic acid ester from Example 3. Themixture was transferred to a 3 ml syringe and placed in an oven at 37°C. to cure overnight.

Example 19

Preparation of Polyurethane: 2.03 grams of the prepolymer of Example 2was mixed with 2.43 grams of the aspartic acid ester from Example 4. Themixture was transferred to a 3 ml syringe and placed in an oven at 37°C. to cure overnight.

Example 20

Preparation of Polyurethane: 8.10 grams of the prepolymer of Example 2was mixed with 5.70 grams of the aspartic acid ester from Example 5. Themixture was transferred to a 3 ml syringe and placed in an oven at 37°C. to cure overnight. The sample was removed from the syringe and cutusing a diamond saw to make a compression test piece. Compressiontesting showed that the material had a compressive stiffness of 0.7 GPaand a yield strength of 20 MPa.

Example 21

Preparation of high MW DL-lactide: 5.15 grams of DL-lactide monomer wasadded to 0.31 grams ethylene glycol and 0.0016 grams Tin(II)2-ethylhexanoate. Mixture heated to 120° C. for 24 hours. Clear, viscousfluid.

Example 22

Preparation of middle MW DL-lactide: 7.19 grams of DL-lactide monomerwas added to 1.56 grams ethylene glycol and 0.0029 grams Tin(II)2-ethylhexanoate. Mixture heated to 120° C. for 24 hours. Clear,slightly viscous fluid.

Example 23

Preparation of low MW DL-lactide: 7.21 grams of DL-lactide monomer wasadded to 3.10 grams ethylene glycol and 0.0030 grams Tin(II)2-ethylhexanoate. Mixture heated to 120° C. for 24 hours. Clear fluid,very low viscosity.

Example 24

Preparation of Polyurethane: 2.05 grams of prepolymer from Example 2 wasmixed with 0.59 grams DL-lactide from Example 21 and 0.0031 gramsdibutyltin dilaurate. The mixture was transferred to a 3 ml syringe andplaced in an oven at 37° C. to cure overnight.

Example 25

Preparation of Polyurethane: 2.02 grams of prepolymer from Example 2 wasmixed with 0.57 grams DL-lactide from Example 22 and 0.0032 gramsdibutyltin dilaurate. The mixture was transferred to a 3 ml syringe andplaced in an oven at 37° C. to cure overnight.

Example 26

Preparation of Polyurethane: 2.05 grams of prepolymer from Example 2 wasmixed with 0.57 grams DL-lactide from Example 23 and 0.0024 gramsdibutyltin dilaurate. The mixture was transferred to a 3 ml syringe andplaced in an oven at 37° C. to cure overnight.

Example 27

Preparation of Polyurethane with braid reinforcement: One 10 mm IDpolypropylene braid with triaxials was filled with polyurethane fromExample 13. Sample was cured at 37° C. in a cylindrical mold overnight.The sample was removed from the syringe and cut using a diamond saw tomake a compression test piece. Compression testing showed that thematerial had a compressive stiffness of 1.3 GPa and a yield strength of69 MPa.

Example 28

Preparation of Polyurethane with braid reinforcement: Two 10 mm IDpolypropylene braids with triaxials were stacked one inside the otherand filled with polyurethane from Example 13. Sample was cured at 37° C.in a cylindrical mold overnight. The sample was removed from the syringeand cut using a diamond saw to make a compression test piece.Compression testing showed that the material had a compressive stiffnessof 1.0 GPa and a yield strength of 44 MPa.

Example 29

Preparation of Polyurethane with braid reinforcement: Four 10 mm IDpolypropylene braids with triaxials were stacked one inside the otherand filled with polyurethane from Example 13. Sample was cured at 37° C.in a cylindrical mold overnight. The sample was removed from the syringeand cut using a diamond saw to make a compression test piece.Compression testing showed that the material had a compressive stiffnessof 1.3 GPa and a yield strength of 69 MPa.

Example 30

Preparation of Polyurethane with braid reinforcement: Four 10 mm IDpolypropylene braids with triaxials were stacked one inside the other,and three 5 mm ID polypropylene braids with triaxials were stacked inthe same way. The smaller ID braids were placed inside the four 10 mm IDbraids and filled with polyurethane from Example 13. Sample was cured at37° C. in a cylindrical mold overnight. The sample was removed from thesyringe and cut using a diamond saw to make a compression test piece.Compression testing showed that the material had a compressive stiffnessof 1.2 GPa and a yield strength of 63 MPa.

Example 31

Preparation of Polyurethane with braid reinforcement: One 10 mm IDpolypropylene braid with triaxials was filled with polyurethane fromExample 14. Sample was cured at 37° C. in a cylindrical mold overnight.The sample was removed from the syringe and cut using a diamond saw tomake a compression test piece. Compression testing showed that thematerial had a compressive stiffness of 1.0 GPa and a yield strength of53 MPa.

Example 32

Preparation of Polyurethane with braid reinforcement: Two 10 mm IDpolypropylene braids with triaxials were stacked one inside the otherand filled with polyurethane from Example 14. Sample was cured at 37° C.in a cylindrical mold overnight. The sample was removed from the syringeand cut using a diamond saw to make a compression test piece.Compression testing showed that the material had a compressive stiffnessof 1.7 GPa and a yield strength of 75 MPa.

Example 33

Preparation of Polyurethane with braid reinforcement: Four 10 mm IDpolypropylene braids with triaxials were stacked one inside the otherand filled with polyurethane from Example 14. Sample was cured at 37° C.in a cylindrical mold overnight. The sample was removed from the syringeand cut using a diamond saw to make a compression test piece.Compression testing showed that the material had a compressive stiffnessof 2.0 GPa and a yield strength of 66 MPa.

Example 34

Preparation of Polyurethane with braid reinforcement: Four 10 mm IDpolypropylene braids with triaxials were stacked one inside the other,and three 5 mm ID polypropylene braids with triaxials were stacked inthe same way. The smaller ID braids were placed inside the four 10 mm IDbraids and filled with polyurethane from Example 14. Sample was cured at37° C. in a cylindrical mold overnight. The sample was removed from thesyringe and cut using a diamond saw to make a compression test piece.Compression testing showed that the material had a compressive stiffnessof 1.7 GPa and a yield strength of 70 MPa.

Example 35

Preparation of Polyurethane with braid reinforcement: One 1.5 mm ID PLAbraid with axials was loaded into a 2 mm ID tube and filled withpolyurethane from Example 13 that had been degas sed with no DBDL.Sample was cured at 70° C. for two days. The sample was removed from thetubing for three point bending test.

Example 36

Preparation of Polyurethane with braid reinforcement: One 1.5 mm ID PLAbraid without axials was loaded into a 2 mm ID tube and filled withpolyurethane from Example 13 that had been degas sed with no DBDL.Sample was cured at 70° C. for two days. The sample was removed from thetubing for three point bending test.

Example 37

Preparation of Polyurethane with braid reinforcement: One 5 mm ID PLAbraid without axials was loaded into a 5 mm ID tube and filled withpolyurethane from Example 13 that had been degassed with no DBDL. Samplewas cured at 70° C. for two days. The sample was removed from the tubingfor three point bending test. Three point bend testing showed that thematerial had a stiffness of 1.2 Gpa and a yield strength of 39 Mpa.

Example 38

Preparation of Polyurethane with braid reinforcement: One 10 mm ID PLAbraid without axials was filled with polyurethane from Example 13 thathad been degassed with no DBDL. Sample was cured at 70° C. in acylindrical mold for two days. The sample was removed from the syringeand cut using a diamond saw to make a compression test piece.Compression testing showed that the material had a compressive stiffnessof 0.8 GPa and a yield strength of 39 MPa.

Example 39

Preparation of Polyurethane with braid reinforcement: One 7 mm ID PLAbraid without axials was placed inside of a 10 mm ID PLA braid withoutaxials and filled with polyurethane from Example 13 that had been degassed with no DBDL. Sample was cured at 70° C. in a cylindrical mold fortwo days. The sample was removed from the syringe and cut using adiamond saw to make a compression test piece. Compression testing showedthat the material had a compressive stiffness of 0.5 GPa and a yieldstrength of 27 MPa.

Example 40

Preparation of Polyurethane with braid reinforcement: One 5 mm ID PLAbraid without axials was placed inside of a 7 mm ID PLA braid withoutaxials and both braids were placed inside of a 10 mm ID PLA braidwithout axials, and the entire stack was filled with polyurethane fromExample 13 that had been degassed with no DBDL. Sample was cured at 70°C. in a cylindrical mold for two days. The sample was removed from thesyringe and cut using a diamond saw to make a compression test piece.Compression testing showed that the material had a compressive stiffnessof 0.8 GPa and a yield strength of 39 MPa.

Modifications Of The Preferred Embodiments

It should be understood that many additional changes in the details,materials, steps and arrangements of parts, which have been hereindescribed and illustrated in order to explain the nature of the presentinvention, may be made by those skilled in the art while still remainingwithin the principles and scope of the invention.

1. A composite implant comprising an injectable matrix material which isflowable and settable, and at least one reinforcing element forintegration with the injectable matrix material, the at least onereinforcing element adding sufficient strength to the injectable matrixmaterial such that when the composite implant is disposed in a cavity ina bone, the composite implant supports the bone; wherein the compositeimplant further comprises a containment bag for disposition within thecavity in the bone; and wherein the at least one reinforcing element isdisposed within the containment bag.
 2. A composite implant according toclaim 1 wherein the at least one reinforcing element comprises at leastone from the group consisting of a flexible reinforcing sheet, aflexible reinforcing rod, and particulates.
 3. (canceled)
 4. (canceled)5. A composite implant according to claim 2 wherein the at least onereinforcing element comprises a flexible reinforcing sheet in the formof a rolled sheet.
 6. (canceled)
 7. A composite implant according toclaim 2 wherein the at least one reinforcing element comprises aflexible reinforcing sheet having a planar cross-section.
 8. A compositeimplant according to claim 2 wherein the at least one reinforcingelement comprises a flexible reinforcing sheet comprising filamentsformed into a textile.
 9. A composite implant according to claim 8wherein the filaments are ordered.
 10. A composite implant according toclaim 8 wherein the filaments are not ordered.
 11. A composite implantaccording to claim 2 wherein the at least one reinforcing elementcomprises a flexible reinforcing sheet comprising filaments connected bya film.
 12. A composite implant according to claim 11 wherein thefilaments are ordered.
 13. A composite implant according to claim 11wherein the filaments are not ordered.
 14. A composite implant accordingto claim 2 wherein the at least one reinforcing element comprises aflexible reinforcing rod comprising filaments held together.
 15. Acomposite implant according to claim 14 wherein the at least onereinforcing element comprises a flexible reinforcing rod and thefilaments are held together by an outer sheath. 16.-18. (canceled)
 19. Acomposite implant according to claim 14 wherein the at least onereinforcing element comprises a flexible reinforcing rod and thefilaments are held together by a compacted connecting structure of atextile or film.
 20. A composite implant according to claim 19 whereinthe connecting structure is compacted by at least one of winding andcompressing.
 21. A composite implant according to claim 14 wherein theat least one reinforcing element comprises a flexible reinforcing rodand the filaments are held together by a binder.
 22. (canceled) 23.(canceled)
 24. A composite implant according to claim 1 wherein the atleast one reinforcing element comprises at least one flexiblereinforcing sheet and at least one flexible reinforcing rod. 25.-27.(canceled)
 28. A composite implant according to claim 1 wherein theinjectable matrix material comprises a polymer. 29.-61. (canceled)
 62. Acomposite implant according to claim 1 wherein the containment bag isconfigured to control the degradation of the composite implant bymodulating the ingress of fluid into the containment bag.
 63. Acomposite implant according to claim 1 wherein the at least onereinforcing element is biodegradable or bioabsorbable.
 64. A compositeimplant according to claim 1 wherein the at least one reinforcingelement comprises from about 5% to about 95% (by volume) of thecomposite implant.